Two Dimensional Laser Galvanometer Scanning Technology for Additive Manufacturing

摘要

In this paper, the barrel-pincushion distortion of the two dimensional laser galvanometer scanning system is analyzed, and investigates the performance of conic fitting algorithm for galvanometer scanning based additive manufacturing (AM) to correct the distortion. Moreover, a scanner delay strategy of galvanometer scanning technology for AM is proposed to improve the geometric precision and surface finish. The proposed scanner delay includes four kinds of delays, which are laser on-off delay, jump delay, mark delay and corner delay. While the effects of these delays are also revealed. To validate the performance of the conic fitting algorithm and the proposed scanner strategy for AM, a stereolithography (SLA) based 3D printer with galvanometer scanning technology is designed and the experiment is conducted on the 3D printer. The results show that the conic fitting algorithm has a contribution to compensate the barrel-pincushion distortion. The results also show that the scanner delay strategy can avoid the excessive material accumulation effectively and correct the contour error which caused by the non-uniform laser power density as well as the inaccurate scanning movement. The work in this paper indicates that the conic fitting algorithm and the scanner delay strategy are effective to improve the geometric precision and surface finish of parts fabricated by AM with galvanometer scanning technology.